Electric switch



April 17, 1928. 1,666,470

, V D. A. SANFORD ELECTRIC SWITCH Filed March 27, 1924 2 Sheets-Sheet 1 flan Sang/ 0 222 gwwmtot 2 Sh eets-Sheet 2 D A SANFORD ELECTRIC SWITCH\ Filed March 27. 1924 April 17, 1928 fldmo'ndsirairiy Patented Apr. 17, 1928.

1' UNITED STATES PATENTTOFFICE.

non-A. sANroan'nEcEAsED, LAT -or WASHINGTON, msrmor orconumnm; ."BY 1 GBETA L. SANFORD, ADMINISTRATRIX, or wnsnmeron. mszrmca: or conuunm.

ELECTRIC SWITCH.

Application rum March 27, 1924. Serial No. 102,200.

The invention relates to an; electric switch especially designed for attachmentto the under surface of the floor of an elevator car and to be operated by .-the foot to" energize an electro-inagnct carried by the car, which clectro-magnet actuates a releasing armature located within a lock casing, said armature forming part of a lock which normally locks a hatchwa'y. door. I

The object of the invention isthe provision of a switch, preferably operated by the foot, which will be of simple construction, sturdy, protected from injury by a casing, and not liable to become inoperative by long and severe service.

The' invention consists in certain novelties of construction and in the combinations of parts as herein set; forth and; claimed.

The accompanying drawings illustrate an example of the embodiment of the invention, the parts being. constructed and combined according to the best mode of procedure devised for the purpose.

Figure 1 is a vertical section of an elevator car and hatchway; the hatchway-door, door lock, electro-magnet carried by the car, and electrical circuits beingshownin elevation. .5 t I x Figure 2 is a bottom plan'view of the box containing the main parts of the switch, the door of the box being removed. r

'Figure is a vertical section ofF'igure 2 on line 3-3, alsoshowing the foot pedal in elevation, and the elevator car floor, box, and hinged box cover in sections.

Figure 4 is a section of Figure 2 on line 4-4, also showing'the car floor and box in section. e t

Figure 5 shows oneof the clamps for the carbon contacts. r

Referring to Figure 1, the letter H designates part of a hatchway, D a sliding hatchway door, L a door lock, C an elevator car, F the floor of the car, S the electric switch, E an eiectro-magnet carried by the car,,I part of the wires of an electriclighting system connected with a suitable source of electrical energy, and V, W the wires connecting the switch with the electromagnet and the wires of 'the lighting system. The switch, when closed, energizes the electrounagnet which, when near to or opposite the lock, attracts an armature within the box casing and unlocks the door.

The switch mechanism, except the pedal and plunger, is inclosed within a box which is securely fastened to the under surfaceof the car floor in any suitable way.

The-numeral 1 designates the metallic box having a door2 hinged at 3, the turned edge 4 normally engaging the wall of the box and holding the door closed.

The pedal 5 is secured to the top end of the plunger 6 which passes loosely through a hole 7 in thecar floor and a bearing 8 in the box. On the threaded end of the plunger is a threaded cap 9, as shown.

A rock shaft 10, angular in cross section, consists of a steel core 11 covered with insulating fibre. 12. The ends of the core have holes 13 within which are loosely 10'- cated flournals 14, 14 of spacing cylinders 15, g

15, tie cylinders being provided with threaded openings 16, 16 to receive anchoring screws 17,17 which pass through holes 18, 18 in the opposite side walls of the box.

To the center of the rock shaft'is secured a lever having a short arm 19 and a long arm 20. This lever consists of two strips of strap iron bent to surround and fit the shaft,riveted together at 21and united by a clamping screw'22. To the top surface of the long arm of the lever is secured a phosphor bronze leaf spring 23, and to the bottom surface is attached a lead weight 24 by a bolt and nut 25, as shown. The cap 9' at the endrof the shank engages the short arm of therlever to rock the shaft and the parts carried' thereby. 7

At opposite sides of the lever and secured to the rock shaft' are two similar projectin arms 26,26, one of which will be describe Two strips of strap iron27 and 28 are bent. at adjacentends to surround the rock shaft andarerunited by a clamping screw 29. Beneath these strips isa third strip 30 bentover at one end 31 and the central portion of the metal partly cut outto form a tongue 32 which is bent downwardly and outwardly and fashioned to form a horizontally projecting seat 33 for a leaf spring hearing. The three strips are united by rivets 34, 35 and 36.

Pivoted in the slot 37 at the end of strip 30 is a spring actuated contact carrier 38 made of sheet brass cut to shape struck up to form flanges 39 and a curved end 40, which .end is loosely located within the slot 37 in strip 30 to form a pivot. A copper contact disk 41 is secured to the end of the carrier.

A hole or opening 42 is formed in the web of the carrier through which passes and projects the tongue 32, and a bent. plate spring 43 having one end riveted to the web of the carrier at 44 and the free end 45 engaging the seat 33 forces the carrier against the turned down end 31 of strip 30. Obviously, as the two contact carriers are each pressed upwardly by a spring 43 the contact disks 41, 41 will each engage the complemental carbon "contact cylinders above when the rock shaft is rotated. far enough, even should the carriers lie in slightly different horizontal'planes.

An angle iron 46 is riveted by rivets 47 to the inner surface of the end of the box. To the under surface of the projecting flange thereof is secured by bolts and nuts 48 a sheet of insulating material 49 which has two holes 50, 50 within each of which is located a threaded bolt 51 secured by a nut 52. These bolts serve as binding posts for the'conductingwires W, W and also hold the clamps 53, 53 which carry the carbon contact cylinders 54, 54. Each of these clamps is made from a cut-out andfashioned piece of sheet brass. As cut-each piece has three projections or wings 55,56 and 57. Wings 55 and 56 are bent to a semicircular shape to form a circular or cylindrical shell within which is located one end of a carbon contact cylinder 54, the bent-out ends having threaded holes to receive a clamping screw 58. The wing 57 is bent over'through an angle of 180 and perforated at 59 for the passage of the shank of the headed bolt 51. A strip of leather issecured at one end to the insulating material 49 by bolt 61, which strip of leather holds in place one of the conducting wires Vii. The two contact carriers 38, as shown by Figure 2, are connected by a flexible current conducting cable 62, the ends thereof being secured in place by threaded screws 63 seated within the metal of the carriers.

When the switch is open, as shown by Figure 3, the end of the long arm 20 of the lever engages the top surface of the sheet of insulating material 49, and the end of the leaf spring 23 engages the inner surface of the top of the box. The spring and the lead weight 24 normally hold the switch open and the pedal and shank raised. A. depression of the pedal closes the switch. The path of the electric current will beobvious from an inspection of Figure 2.

From the foregoing description and drawings it will be clear that the switch fulfills the conditions, set forth as the object of the invention.

.What is claimed as new is:

wires secured to the said posts; and a conducting wire or cable for the passage of current between the contacts supported by the carriers.

2. The subject-matter of claim 1 with the addition ofa weight upon one arm of the lever normally to hold the switch in anopen position.

'3. The subject-matter of claim 1 with the addition of a spring secured to one arm of the lever, which spring engages the surface of the box normally to-hold the an open'position.

4. The subject-matter of claim lwith the addition of clamps for the contacts, said clamps being insulated and secured in position by the binding posts.

5. The subject-matter of claim 1 when the means for insulating the binding posts and contacts consists of a plate of insulating material supported inside the box.

6. The subject-matter of claim 1 when the rock' shaft hasinsulating' material at its exterior surface.

7 The subject-matter of claim 1 when the contact carriers are spring mounted relative to the rock shaft.

8. The subject-matter of claim 1 when the lever is insulated from the rock shaft.

9. The subject-matter of claim 1 when the means for insulatingthe contacts consists of a sheet of insulating material, and the long arm of. the lever is adapted to engage said sheet of material and limit the rocking movement of the rock shaft.

GRETA L. SANFORD,

switch in V 

